Liu Yinong

Different Dose Rate Radiation Effects on Linear CCDs

Charge coupled devices (CCD) have been tested at widely differing dose rates to examine the radiation tolerance dependence on the dose rates. The test results show a maximum tolerance of CCDs at 10.2 rad(Si)/sec, a slight reduction in tolerance at 34.8 rad(Si)/sec and a quite precipitous roll off when moving down to 1 rad(Si)/sec and 0.1 rad(Si)/sec. The degradation of the dummy output voltages and the dark signal voltages are compared at the dose rates of 0.1,1.0,10.2 and 34.8 rad(Si)/sec, respectively. It shows that the degradation levels depend on the dose rates. The CCDs are divided into two groups during 60Co γ irradiation. Either the output amplifiers or the photo sensing and the shift register areas are shielded with Pb during the irradiation tests.

Development of a multi-channel readout ASIC for a fast neutron spectrometer based on GEM-TPC

Fast neutron spectrometers with high energy resolution are required in some research fields such as nuclear physics and thermo-nuclear fusion plasma diagnostics. In this study, a fast neutron spectrometer based on GEM-TPC has been proposed, which uses the energy of recoiled protons and the recoil angles from reconstructed proton tracks to derive the neutron energy. Compared to the traditional spectrometers, this new method has merits such as high detection efficiency and excellent discrimination ability for neutron from gamma.

Simulation for signal charge transfer of charge coupled devices

Physical device models and numerical processing methods are presented to simulate a linear buried channel charge coupled devices (CCDs). The dynamic transfer process of CCD is carried out by a three-phase clock pulse driver. By using the semiconductor device simulation software MEDICI, dynamic transfer pictures of signal charges cells, electron concentration and electrostatic potential are presented. The key parameters of CCD such as charge transfer efficiency (CTE) and dark electrons are numerically simulated. The simulation results agree with the theoretic and experimental results.